This invention relates to apparatus for dispensing liquid as an atomised spray and in particular but not exclusively to apparatus for dispensing a water-borne liquid product.
Recent trends in the manner in which hair sprays and the like have been delivered in aerosol form have resulted in liquid products being dispensed in aqueous solution by manually operated pumps for example. The use of environmentally damaging volatile propellants is thereby avoided, but users find the characteristics of the resulting water-borne spray to be less desirable in some respects.
It has been proposed in U.S. Pat. No. 4057176 to improve the quality of a water-borne spray by dispensing compressed air simultaneously with dispensed liquid in order to both assist the breakup of the spray into finely divided particles and to produce a drier spray in the sense that some of the water content is evaporated from the sprayed liquid as a consequence of compressed air being entrained in the spray. It has also been proposed in U.S. Pat. No. 5100029 to provide a delivery means with an actuator which is constructed so as to provide compressed air during actuation by a pumping action associated with manual depression of the actuator.
In each of the above disclosures the compressed air is mixed with a flow of liquid from a delivery means in a mixer chamber upstream of a nozzle and the subsequent mixture is then dispensed through a nozzle as an atomised spray.